Health care remains at the foremost frontiers for scientific research. The need to discover and develop cost-effective and safer medications is ever increasing.
Hydrogels, both of synthetic and natural origin have emerged for example as suitable scaffolds for 3D cell culture. The network of interconnected pores in hydrogels allows for retention of a large amount of biological fluid, facilitates transport of oxygen, nutrients and waste. Furthermore, most hydrogels can be formed under mild cytocompatible conditions and the biological properties can be modulated by surface chemistry. Engineered hydrogels with modified mechanical, chemical and biological properties have the potential to mimic the ECM and thus establish their utility in 3D cell culture. Commercial products for 3D cell culturing are for example PuraMatrix™ (3DM Inc.) and Matrigel (BD Biosciences). PuraMatrix™ is a hydrogel of self-assembled peptide nanofibers wich resembles the structure of natural fibrillar collagen in ECM with fiber diameter 5-10 nm. It has also high water content, typically 99.5%. U.S. Pat. No. 7,449,180 and WO 2004/007683 disclose peptide hydrogels. Matrigel is gelatinous protein mixture secreted by mouse tumor cells. The mixture resembles the complex extracellular environment found in many tissues and is used by cell biologists as a substrate for cell culture. MaxGel™ ECM Matrix (Sigma-Aldrich), which includes a mixture of human ECM components, forms a gel in ambient temperature.
Conventional bacterial cellulose has been used in wound healing membranes and as a scaffold in cell culture. The limitation in the use of bacterial cellulose is the inherent structure of the fermented material; upon cultivation, bacterial cellulose is formed as very tight membranes in air water interphase in the fermenter.
Hydrogel materials are widely used in culturing tasks where hydrophilic supporting material is needed, for example agar type hydrocolloids are used in plant cell, bacterial, and fungi culturing for various microbiological purposes.
U.S. Pat. No. 5,254,471 discloses a carrier for culturing cells made of ultra fine fibers. WO 2009/126980 discloses cellulose-based hydrogel, which contains cellulose exhibiting an average degree of polymerization of 150-6200.